New York Mayor Michael Bloomberg's record on everything from crime to education is on the line as his would-be successors face off in their city's primaries on Tuesday. But another vote on his legacy is taking place halfway across the country in Colorado.

Two Colorado state senators there are facing recall elections — the first in the state's history — that are seen as a referendum on Bloomberg's national campaign to enact tougher gun laws, as well as the National Rifle Association's efforts to stop him.

The recalls target Democrats Angela Giron of Pueblo and State Senate President John Morse of Colorado Springs, both of whom helped pass four new gun-control laws last year after the Aurora shooting massacre that left 12 people dead and 58 injured in a movie theater. The billionaire Bloomberg, founder of Mayors Against Illegal Guns, wrote a $350,000 personal check for the anti-recall campaigns, and the NRA kicked in $368,000 on the other side.

Giron has called Election Day a do-or-die moment for Bloomberg's group, which has been a leading booster of efforts in Colorado and across the country to ban high-capacity ammunition magazines, expand background checks, and impose other new restrictions on gun purchases. "For Mayors Against Illegal Guns, if they lose even one of these seats, they might as well fold it up," Giron recently told The New Republic.

Morse, who would be retiring next year anyway due to term limits, is considered more vulnerable, since he is in a swing district, while Giron's seat is generally seen as a safe one for Democrats. Both have money on their side. The vote has involved more than $3.5 million in campaign contributions, nearly $3 million of it for the anti-recall effort.

The chance to oust the Democrats despite that advantage is what makes gun-rights advocates hope that even a partial victory in Colorado will resonate nationwide as a warning to other lawmakers not to support new restrictions on gun ownership. Emily Miller at The Washington Times says that with Bloomberg and his allies outspending the NRA by such a wide margin, a loss in the Colorado recalls could "mark a turning point in a string of gun-control advocates in the wake of the Newtown, Conn., tragedy."

Ashley Killough at CNN sums up the message the NRA is hoping to send this way: "Mess with guns and this could happen to you." But gun-control advocates are just as hopeful that the recall will mark a turning point for their side, she says. "If the senators win, it could signal a significant show of public support at the polls for regulations meant to curb gun violence," Killough says. "Gun control advocates also argue a victory would deal a major blow to what they consider the powerful voices that control the debate."

And money isn't the only trump card Democrats hold. "While a majority of Coloradans dislike the gun control law, a roughly equal number oppose the recall," says Tim Murphy at Mother Jones. "And the returns so far are promising: In Giron's district, supporters have built up a 3-1 advantage in early voting. The idea that bucking the NRA meant an almost-certain political death has always been a myth. With all eyes on Colorado, people might just finally take notice."

If voters approve the recalls, the Democratic majority in the state Senate could be trimmed to 18-17, from 20-15. That would bolster the GOP on issues from gun-control to abortion, but there's a catch. Morse's most likely replacement as Senate president would be state Sen. Morgan Carroll (D), a champion of gun-control whose district includes Aurora. So there might be more clashes to come.